2) Inaba sensei is NOT an expert of Kashima Shin-ryu. You can do a search of Karl Friday's (menkyo kaiden in the system) posts on e-budo and I think Aikido Journal re this. Inaba learned the first level sword kata and leavened them heavily with aikido. He may be expert at what he does, and it may seem like a small thing to outsiders, but to initiates in the systems, what he does is radically different from the ryu itself. It is true, tho', that Yamaguchi sensei was quite influenced by Inaba's sword - and it could clearly be seen in his aikido technique.

One of the problems we have here is that there is no "style" we can talk about. Saito Sensei's system of weapons trainning is the most organized and comprehensive but it is what he and the Founder did together at a certain time and place.

It is quite vague, even obscured by political currents, exactly what sword training O-sensei underwent but he did not have a teaching license in any particular school of kenjutsu as far as one can determine.

To say that O-Sensei didn't teach weapons would be incorrect in that it was almost impossible to train with O-Sensei when he didn't use a weapon to illustrate the points he was trying to make and show the principles of his art. However, it is true that he didn't teach any systematic weapons program. But, according to Saotome Sensei, if you asked O-Sensei a question about Aikido he would , as likely as not, pull a bokken off the rack to illustrate what he wished to teach.

While interesting to have an idea where various Aikido teachers received their weapons training, it is actually misleading in some sense. Although there is Kashima style sword in O-Sensei's and Saito Sensei's work, neither was a Kashima teacher. So their interpretation simply isn't Kashima. Inaba Sensei, as Ellis Amdur points out, wasn't certified as an instructor and therefore one can't even consider what he does as Kashima sword. The same can be said for what Tissier Sensei and Gleason Sensei do. In the sword work of Imaizumi Sensei and Saotome Sensei there is technique which might seem similar to some techniques within Itto, Kashima, and Yagyu styles, techniques or groups of techniques taken out of the proper context simply cease to be a part of the school. They can not be separated from their own styles.

I trained for a relatively short period in both the Buko Ryu Naginata and the Araki Ryu with Amdur Sensei. While what I learned from doing that training influenced what I do in my Aikido in a very positive manner, it would be almost misleading to try to pick out the places where a specific technique or movement might have some similiarity to something I did when training in those styles. The instant those elements were taken out of their original context and put into my Aikido they simply ceased to be Buko Ryu or Araki Ryu in any meaningful sense.

In the same way that every Aikido teacher has a different way of interpreting Aikido, the major teachers of Aikido tend to have their own interpretations of how weapons are utilized within Aikido. To say that there is anything which one could define as aikiken in the same way that Kashima Shin Ryu or Katori Shinto Ryu means something very specific simply isn't true. There is no one style of Aikido and there isn't any one style of weapons use.